Cassava defoliation and utilization of cassava foliage in ruminant feeding

Three studies were conducted to determine the effect of cassava defoliation on agronomic, economic and nutritive viability of integrating livestock production under cassava based farming system. In study 1, effect of two cutting intervals, 5 and 7 months after planting (MAP) and 5 and 9 MAP and the effect of four defoliation percentage (0 percent, 25 percent, 50 percent, and 75 percent) on dry matter yield (DMY), protein yield and tuber yield were evaluated in a 2 x 3 factorial in RCBD. Total DMY (t/ha) was linearly increased (P0.01) with increasing percentage defoliation (Y0.05) with different defoliation percentage and cutting intervals. However, the increased DMY with increasing defoliation resulted a linear increased in total CP yield with increasing defoliation. In addition, tuber yield (t/ha) was linearly increased with increasing defoliation at Y = 25.42 + 0.07X. In study 2, feeding value of cassava foliage (CSF) was evaluated in cattle to determine the voluntary feed intake, dry matter digestibility (DMD) and growth performance. Average daily voluntary feed intake of fresh CSF was 33.68 kg/day and DMD at 62.95 percent which indicated acceptability of fresh CSF as ruminant feed. Two months comparative feeding of CSF and signal grass showed that animals fed with CSF had 51 percent higher ADG (0.71 kg/day) compared to animals fed with grasses (0.47 kg/day). In study 3, computer model was developed to simulate the agronomic, economic and nutritive aspect of integrating livestock production under cassava based farming system. Metabolic and growth simulation using values of Kearl (1982) resulted to metabolic and growth values close to the feeding trial. Comparative feeding with napier and levels of supplementation showed maximum growth and economic performance at 100 percent CSF feeding and 2 kg of high energy concentrate supplementation. Agronomic simulation showed that to maintain positive soil N balance and productivity at 5 tons DM/ha of defoliated cassava application of 60 kg N/ha/year is needed. The above production is sufficient to support 4 steers at 4 months fattening period at 100 percent CSF feeding. Results of the 3 studies indicated agronomic, nutritive and economic viability of integrating livestock production under cassava based farming system with defoliation